Discrimination of Blur in Normal and Amblyopic Eyes

Abstract

The ability to respond and accommodate appropriately to a defocused and perceptually blurred target requires one to be able to discriminate changes in overall contrast and edge sharpness (Fry., 1955; Fujii et al, 1970; Hamerly and Dvorak, 1981; Watt and Morgan, 1983; Ciuffreda and Rumpf, 1985; Ciuf-freda et al., 1987) as well as other attributes (such as chromatic aberration, spherical aberration, etc.) of the retinal image (Fry., 1955; Campbell and West-heimer, 1959; Fujii et al., 1970). Inability to do so would adversely affect accommodative accuracy and quality of the retinal image (Fry., 1955; Fujii et al., 1970; Ciuffreda and Rumpf, 1985). This, in turn, could impair one’s visual resolution and visual efficiencY., perhaps even leading to general visual discomfort. Such results might be predicted to be found, and indeed exaggerated, in amblyopic eyes in which overall reduced sensitivity is the norm (Schapero, 1971; Ciuffreda et al., 1991).